[PATCH] uml: tls support: hack to make it compile on any host

Copy the definition of struct user_desc (with another name) for use by
userspace sources (where we use the host headers, and we can't be sure about
their content) to make sure UML compiles.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/include/os.h

@@ -13,6 +13,7 @@
 #include "kern_util.h"
 #include "skas/mm_id.h"
 #include "irq_user.h"
+#include "sysdep/tls.h"
 
 #define OS_TYPE_FILE 1 
 #define OS_TYPE_DIR 2 
@@ -238,10 +239,10 @@ extern int helper_wait(int pid);
 
 
 /* tls.c */
-extern int os_set_thread_area(void *data, int pid);
-extern int os_get_thread_area(void *data, int pid);
-/* umid.c */
+extern int os_set_thread_area(user_desc_t *info, int pid);
+extern int os_get_thread_area(user_desc_t *info, int pid);
 
+/* umid.c */
 extern int umid_file_name(char *name, char *buf, int len);
 extern int set_umid(char *name);
 extern char *get_umid(void);

arch/um/include/sysdep-i386/tls.h

+#ifndef _SYSDEP_TLS_H
+#define _SYSDEP_TLS_H
+
+# ifndef __KERNEL__
+
+/* Change name to avoid conflicts with the original one from <asm/ldt.h>, which
+ * may be named user_desc (but in 2.4 and in header matching its API was named
+ * modify_ldt_ldt_s). */
+
+typedef struct um_dup_user_desc {
+	unsigned int  entry_number;
+	unsigned int  base_addr;
+	unsigned int  limit;
+	unsigned int  seg_32bit:1;
+	unsigned int  contents:2;
+	unsigned int  read_exec_only:1;
+	unsigned int  limit_in_pages:1;
+	unsigned int  seg_not_present:1;
+	unsigned int  useable:1;
+} user_desc_t;
+
+# else /* __KERNEL__ */
+
+#  include <asm/ldt.h>
+typedef struct user_desc user_desc_t;
+
+# endif /* __KERNEL__ */
+#endif /* _SYSDEP_TLS_H */

arch/um/include/sysdep-x86_64/tls.h

+#ifndef _SYSDEP_TLS_H
+#define _SYSDEP_TLS_H
+
+# ifndef __KERNEL__
+
+/* Change name to avoid conflicts with the original one from <asm/ldt.h>, which
+ * may be named user_desc (but in 2.4 and in header matching its API was named
+ * modify_ldt_ldt_s). */
+
+typedef struct um_dup_user_desc {
+	unsigned int  entry_number;
+	unsigned int  base_addr;
+	unsigned int  limit;
+	unsigned int  seg_32bit:1;
+	unsigned int  contents:2;
+	unsigned int  read_exec_only:1;
+	unsigned int  limit_in_pages:1;
+	unsigned int  seg_not_present:1;
+	unsigned int  useable:1;
+	unsigned int  lm:1;
+} user_desc_t;
+
+# else /* __KERNEL__ */
+
+#  include <asm/ldt.h>
+typedef struct user_desc user_desc_t;
+
+# endif /* __KERNEL__ */
+#endif /* _SYSDEP_TLS_H */

arch/um/os-Linux/tls.c

 #include <errno.h>
 #include <sys/ptrace.h>
 #include <asm/ldt.h>
+#include "sysdep/tls.h"
 #include "uml-config.h"
 
 /* TLS support - we basically rely on the host's one.*/
@@ -18,9 +19,8 @@
 #define PTRACE_SET_THREAD_AREA 26
 #endif
 
-int os_set_thread_area(void *data, int pid)
+int os_set_thread_area(user_desc_t *info, int pid)
 {
-	struct user_desc *info = data;
 	int ret;
 
 	ret = ptrace(PTRACE_SET_THREAD_AREA, pid, info->entry_number,
@@ -32,9 +32,8 @@ int os_set_thread_area(void *data, int pid)
 
 #ifdef UML_CONFIG_MODE_SKAS
 
-int os_get_thread_area(void *data, int pid)
+int os_get_thread_area(user_desc_t *info, int pid)
 {
-	struct user_desc *info = data;
 	int ret;
 
 	ret = ptrace(PTRACE_GET_THREAD_AREA, pid, info->entry_number,
@@ -49,10 +48,10 @@ int os_get_thread_area(void *data, int pid)
 #ifdef UML_CONFIG_MODE_TT
 #include "linux/unistd.h"
 
-_syscall1(int, get_thread_area, struct user_desc *, u_info);
-_syscall1(int, set_thread_area, struct user_desc *, u_info);
+_syscall1(int, get_thread_area, user_desc_t *, u_info);
+_syscall1(int, set_thread_area, user_desc_t *, u_info);
 
-int do_set_thread_area_tt(struct user_desc *info)
+int do_set_thread_area_tt(user_desc_t *info)
 {
 	int ret;
 
@@ -63,7 +62,7 @@ int do_set_thread_area_tt(struct user_desc *info)
 	return ret;
 }
 
-int do_get_thread_area_tt(struct user_desc *info)
+int do_get_thread_area_tt(user_desc_t *info)
 {
 	int ret;